rickets is a nutritional disorder that can develop if you do not get enough vitamin d calcium or phosphate rickets leads to poor functioning of a bone s growth plate growing edge softened and weakened bones stunted growth and in severe cases skeletal deformities
Hence, a 20-year period of the patent usually gives manufacturers a chance to recoup the cost of developing a new drug. When a drug patent expires, any pharmaceutical company can manufacture and sell the drug. A drug, which is produced and distributed without patent protection is called a generic drug.
How long a patent lasts depends on when the application was filed with the U.S. Patent and Trademark Office. Patents Filed Through June 17, 1995 For U.S. patents filed through June 17, 1995, the patent lasts for 17 years from the date the patent is issued, provided that the fees necessary to keep the patent in force (maintenance fees) are paid.